From: Richard Broersma <richard.broersma@gmail.com>
To: Gianvito Pio <pio.gianvito@gmail.com>
Cc: pgsql-sql@postgresql.org
Subject: Re: Type inheritance
Date: Sat, 6 Jun 2009 07:30:57 -0700
Message-ID: <396486430906060730t1afd39a9p49b056158b1d2194@mail.gmail.com> (raw)
In-Reply-To: <5eca56860906060010y4177b88apcf587d62f7286b5d@mail.gmail.com>
References: <5eca56860906050330w6171b327k95881b13c4dca466@mail.gmail.com>
<4A294A00.5020802@gmail.com>
<5eca56860906060010y4177b88apcf587d62f7286b5d@mail.gmail.com>
On Sat, Jun 6, 2009 at 12:10 AM, Gianvito Pio<pio.gianvito@gmail.com> wrote:
> That value doesn't have to be fixed, but I want to define it in a
> way that it changes its structure when the sensor type changes. For
> example, for Temperature sensor I would like to have just a float number,
> but for the humidity I could need of absolute and relative humidity
> (2 floats). I'd just like to know if I can say that the VALUE is a composite
> type...that I have then to specialize in Temp Type and Humidity type...using
> them in their particular case.
I think that best solution for what you want to achieve is to design
you own vertically partitioned table hierarchy. PostgreSQL's table
inheritance isn't going to allow that relationships that you may want
between the sub-types.
Another PostgreSQL specific feature that allows for hierarchical data
is the contrib module h-store. Its kind-of like EAV for a column
instead of a table.
--
Regards,
Richard Broersma Jr.
Visit the Los Angeles PostgreSQL Users Group (LAPUG)
http://pugs.postgresql.org/lapug
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To: pgsql-sql@postgresql.org
Cc: richard.broersma@gmail.com, pio.gianvito@gmail.com
Subject: Re: Type inheritance
In-Reply-To: <396486430906060730t1afd39a9p49b056158b1d2194@mail.gmail.com>
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